The forms of elongate robotic instruments vary widely, but many elongate robotic instruments share the features of a mechanical, movable structure under some form of control. The mechanical structure or kinematic chain (analogous to the human skeleton) of an elongate robotic instrument can be formed from several links (analogous to human bones), actuators (analogous to human muscle), and joints between the links, permitting one or more degrees of freedom of motion of the links. A continuum or multi-segment elongate robotic instrument can be a continuously curving device, like an elephant trunk for example. An example of a continuum or multi-segment elongate robotic instrument is a snake-like endoscopic device.
Snake-like endoscopic devices can transfer forces from an actuator to particular sections of links in the snake-like device to effect articulation of that section or link. During articulation, these links are subjected to large stresses that can result in breakage or failure of the link and thus, failure of the endoscopic device. These failures typically occur at the weak point between links, such as at the joints.
A typical robotic link is made from a metal or alloy, such as aluminum or stainless steel. The links can be manufactured by laser cutting tubes, by laser sintering, by metal injection molding, or other processes as known in the art. Furthermore, a snake-like endoscopic device can often include several types of links, such as distal and proximal links for attachment to actuators, and intermediate links therebetween. However, manufacturing elongate robotic devices with these materials, as well as needing several different types of links for each device, can be expensive and add to the cost of an elongate robotic instrument.
An elongate robotic instrument, and more particularly a link that is used to make up the elongate robotic instrument, is therefore needed that can be manufactured efficiently and inexpensively while still being able to withstand the stresses imposed upon it during normal use.